Variance Estimation of Imputed Estimators of Change for Repeated Rotating Surveys

A common problem in survey sampling is to compare two cross‐sectional estimates for the same study variable taken from two different waves or occasions. These cross‐sectional estimates often include imputed values to compensate for item non‐response. The estimation of the sampling variance of the estimator of change is useful to judge whether the observed change is statistically significant. Estimating the variance of a change is not straightforward because of the rotation in repeated surveys and imputation. We propose using a multivariate linear regression approach and show how it can be used to accommodate the effect of rotation and imputation. The regression approach gives a design‐consistent estimation of the variance of change when the sampling fraction is small. We illustrate the proposed approach using random hot‐deck imputation, although the proposed estimator can be implemented with other imputation techniques.     

Self-employment and job generation in metropolitan areas, 1969–2009

Many regional development policy initiatives assume that entrepreneurial activities promote economic growth. Empirical research has presented rationale for this argument showing that small firms create proportionally more new jobs than large firms. However, little research has been performed on the issue of net job generation at the urban level, particularly when self-employment is considered as an indicator of entrepreneurial activities. This paper investigates to what extent US metropolitan areas in the 1969–2009 period characterized by relatively high rates of self-employment also have shown relatively high rates of subsequent total employment growth. The analysis corrects for the influence of sectoral composition, wage level, educational attainment, presence of research universities and size of the metropolitan area to measure the extent to which the number and quality of self-employed in a region contribute to total employment growth. It finds the relationship between self-employment rates and subsequent total employment growth to be positive on average during the 40-year period but to weaken over time.     

Institutional framework,corporate ownership structure,and R&D investment: an international analysis

We combine agency theory with the law and finance approach to analyze how the legal protection of investors and the corporate ownership structure affect corporate investment in research and development (R&D). We use information from 956 firms from the five most R&D-intensive industries in 19 developed countries. Our results show that better protection of investors’ rights by the institutional environment has a positive influence on corporate R&D. We also find that corporate ownership concentration works as a substitute for legal protection. This finding means that R&D investment of the firms in the countries with poor legal protection increases as ownership becomes more concentrated. Our results also show that the identity of shareholders has a relevant effect: Whereas banks and nonfinancial institutions as shareholders result in lower R&D, institutional investors as shareholders increase corporate investment in R&D.     

Exploring the big jump in the Spanish unemployment rate: Evidence on an ‘added-worker’ effect

Spain is destroying more jobs than any other European country. In the third quarter of 2009, the unemployment rate stood at 17.9%, the second-highest rate in the 27-nation EU and the highest rate in the euro area (EA-16). The exponential growth of the Spanish unemployment rate is the by-product of falling employment rates. However, there is a second explanation which is often overlooked by unemployment forecasters: changes in labour force participation rates. On the one hand, in times of recession participation rates tend to increase in order to safeguard sustainable household incomes. This phenomenon is known as the ‘added-worker’ effect. On the other hand, there is also an opposite effect in that individuals leave the labour force in recessions because chances to find employment are low. This is the ‘discouraged-worker’ effect. Applying a threshold cointegration model to Spanish quarterly data over the period 1976-2008, we find that the added-worker effect dominates the discouraged-worker effect, but only when unemployment is below 11.7%. Above this threshold, the two effects cancel each other out so that the participation rate is not influenced by further deteriorations of economic conditions. Since Spain recently passed the 11.7% unemployment threshold, our model predicts that there will be no further increases in the participation rate in the near future.     

Equilibrium portfolios in the neoclassical growth model

This paper studies equilibrium portfolios in the standard neoclassical growth model under uncertainty with heterogeneous agents and dynamically complete markets. Preferences are purposely restricted to be quasi-homothetic. The main source of heterogeneity across agents is due to different endowments of shares of the representative firm at date 0. Fixing portfolios is the optimal equilibrium strategy in stationary endowment economies with dynamically complete markets. However, when the environment displays changing degrees of heterogeneity across agents, the trading strategy of fixed portfolios cannot be optimal in equilibrium. Very importantly, our framework can generate changing heterogeneity if and only if either minimum consumption requirements are not zero or labor income is not zero and the value of human and non-human wealth are linearly independent.     

A kernel-based method for nonparametric estimation of variograms

Variogram estimation plays an important role in many areas of spatial statistics. Potential areas of application include biology, ecology, economics and meteorology. However, it is common that, for example under highly correlated patterns, traditional estimators can not reflect all the spatial features or dependencies. In this paper, we present an alternative distribution-free estimator based on nearest-neighbour estimation with a non-constant smoothing field that is better able to adapt to spatially varying features of the data pattern. We present a simulation study to compare our new estimator to a nearest-neighbour estimator built with a constant smoothing parameter and to the classical variogram estimator. We apply our method to analyze two ecological data sets.     

Economic impacts of developing a biofuel industry in Mozambique

ABSTRACT

Mozambique is one of the most promising African countries for producing biofuels and the national biofuel policy of 2009 identifies measures to incentivize biofuel production. Demand for biofuels in the Southern African Development Community is expected to increase over the next few years as 7 of its 15 member states have implemented or proposed the implementation of blending mandates by 2020. South Africa is one of these countries. Using a dynamic recursive computable general equilibrium (CGE) model, we estimate the impacts of expanding biofuel production in Mozambique under both commercial and smallholder-type farming models, including and excluding bagasse cogeneration.     

Incentive compatibility constraints and dynamic programming in continuous time

This paper is devoted to the study of infinite horizon continuous time optimal control problems with incentive compatibility constraints that arise in many economic problems, for instance in defining the second best Pareto optimum for the joint exploitation of a common resource, as in Benhabib and Radner [Benhabib, J., Radner, R., 1992. The joint exploitation of a productive asset: a game theoretic approach. Economic Theory, 2: 155–190]. An incentive compatibility constraint is a constraint on the continuation of the payoff function at every time. We prove that the dynamic programming principle holds, the value function is a viscosity solution of the associated Hamilton–Jacobi–Bellman (HJB) equation, and that it is the minimal supersolution satisfying certain boundary conditions. When the incentive compatibility constraint only depends on the present value of the state variable, we prove existence of optimal strategies, and we show that the problem is equivalent to a state constraints problem in an endogenous state region which depends on the data of the problem. Some economic examples are analyzed.     

Synamic banking: a reconsideration

Financially intermediated and stock market consumption-investmentallocations, with and without governmental interventions, arecompared in a welfare sense in overlapping generation economieswith (and without) shocks to agents' intertemporal preferences.We first show that, in economies with preference shocks, governmentalinterventions subject to the same information requirements asthose imposed on financial intermediaries, lead to stock marketallocations that are not inferior to those attained under financialintermediation. Second, we argue that the necessary interventionsare qualitatively no different from those required to implementstationary optimal allocations in OLG models without shocksto agents' intertemporal consumption preferences.